**Areas related to Circles ncert solutions Chapter 12 Exercise 12.1 Question 4**

**4.** The wheels of a car are of diameter 80 cm each. How many complete revolutions does each wheel make in 10 minutes when the car is travelling at a speed of 66 km per hour?

**Solution:**

**Diameter of wheel = 80 cm**

**Radius of wheel= cm**

Distance traveled by car in 10 minutes = speed of car x time = **km**

11 km = 11,000,00 cm

Circumference of circle = **cm**

Therefore, 1 Revolution = **cm**

1 cm = revolutions

**11,000,00 cm** = **revolutions**